Pterygoplichthys up close



Wehrle, B.A., A. Herrel, B-Q Nguyen-Phuc, S. Maldanado Jr., R.K. Dang, R. Agnihotri, Z. Tadić, D.P. German. (2020) Rapid dietary shift in Podarcis siculus resulted in localized changes in gut function. Physiological and Biochemical Zoology 93: 396-415 [pdf]

McCauley, M., D.P. German, N.K. Lujan, C.R. Jackson. (2020) Gut microbiomes of sympatric Amazonian wood-eating catfishes (Loricariidae) reflect host identity and little role in wood digestion. Ecology and Evolution 10: 7117-7128. [pdf] 

Heras, J., M. Chakraborty, J.J. Emerson, D.P. German. (2020) Genomic and biochemical evidence of dietary adaptation in a marine herbivorous fish. Proceedings of the Royal Society B 287: 20192327
. [pdf] Supplemental Material

Nguyen-Phuc, B.Q., C. Demetropolous, S. Stewart, P. Saffarinia, J.D. Bastian-Salgado, E. Hawkins, A.R. Frederick, D.P. German. (2020) Nutritional physiology of Santa Ana Sucker, Catostomus santaanae: a threatened freshwater fish endemic to southern California. Acta Zoologica (In Press) [pdf]


Leigh, S.C., Y.P. Papastamatiou, and D.P. German (2018) Seagrass digestion by a notorious "carnivore". Proceedings of the Royal Society B 285: 20181583 [pdf] Supplemental Material Supplemental Methods

Santos, A.*, A.R. Frederick*, B.A. Higgins, A. Carrillo, A. Carter, K.M. Dickson, D.P. German, and M.H. Horn (2018) Egg cannibalism in fishes: the beach-spawning grunion (Leuresthes tenuis) eats and digests its own eggs. Journal of Fish Biology 93: 282-289 [pdf] *these authors contributed equally to this article.

Leigh, S.C., B-Q. Nguyen-Phuc, and D.P. German (2018) The effects of protein and fiber content on gut structure and function in zebrafish (Danio rerio). Journal of Comparative Physiology B 188: 237-253 [pdf] Supplemental Table 1


Leigh, S.C., Y.P. Papastamatiou, and D.P. German (2017) The nutritional physiology of sharks. Reviews in Fish Biology and Fisheries 27: 561-585 [pdf]

German, D.P., D. Raven, and N.M. Aguilar-Roca (2017) Floating fishes: an activity investigating overfishing, buoyancy, and gas compressibility. American Biology Teacher 79: 49-54 [pdf]  Supplemental Materials

Clements, K.D., D.P. German, J. Piche, A. Tribollet, and J.H. Choat. (2017) Integrating ecological roles and trophic diversification on coral reefs: multiple lines of evidence identify parrotfishes as microphages.  Biological Journal of the Linnean Society 120: 729-751 [pdf]


Connor, K., A. Sung, N.S. Garcia, A. Gracey, and D.P. German (2016) Modulation of digestive physiology and biochemistry in Mytilus californianus in response to feeding level acclimation and intertidal microhabitat.  Biology Open 5: 1200-1210 [pdf]

German, D.P.*, D.M. Foti*, J. Heras, H. Amerkhanian, and B.L. Lockwood (2016) Elevated gene copy number does not always explain elevated amylase activities in fishes.  Physiological and Biochemical Zoology 89: 277-293 *These authors contributed equally to this work [pdf]  Supplemental materials


Jhaveri, P., Y. Papastamatiou, and D.P. German (2015) Digestive enzyme activities in the guts of bonnethead sharks (Sphyrna tiburo) provide insight into their digestive strategy and evidence for microbial digestion in their hindguts. Comparative Biochemistry and Physiology A: 189: 76-83 [pdf]

German, D.P., and S.D. Allison (2015) Drying and substrate concentrations interact to inhibit decomposition of carbon substrates added to combusted Inceptisols from a boreal forest. Biology and Fertility of Soils 51: 525-533 [pdf]

Sullam, K.E., C.M. Dalton, J.A. Russell, S.S. Kilham, R. El-Sabaawi, D.P. German, and A.S. Flecker. (2015) Changes in digestive traits and body nutritional composition accommodate a trophic niche shift in Trinidadian guppies. Oecologia 177: 245-257 [pdf]

German, D.P., A. Sung, P.K. Jhaveri, and R. Agnihotri (2015). More than one way to be an herbivore: convergent evolution of herbivory using different digestive strategies in prickleback fishes (family Stichaeidae). Zoology 118: 161-170 [pdf] Supplemental materials Elsevier write up about the paper


Allison, S.D., S.S. Chacon, and D.P. German (2014) Substrate concentration constraints on microbial decomposition. Soil Biology and Biochemistry 79: 43-49. [pdf]

German, D.P., A.K. Gawlicka, and M.H. Horn (2014) Evolution of ontogenetic dietary shifts and associated gut features in prickleback fishes (Teleostei: Stichaeidae). Comparative Biochemistry and Physiology B 168: 12-18 [pdf]

Kim, K.H., M.H. Horn, A.E. Sosa, and D.P. German (2014) Sequence of an a-amylase gene in four related species of prickleback fishes (Teleostei: Stichaeidae): ontogenetic, dietary, and species-level effects. Journal of Comparative Physiology B 184: 221-234 [pdf]


Bach, C.E., D.D. Warnock, D.J. Van Horn, M.N. Weintraub, R.L. Sinsabaugh, S.D. Allison, and D.P. German (2013)  Measuring phenol oxidase and peroxidase activities with pyrogallol, l-DOPA, and ABTS: effect of assay conditions and soil type. Soil Biology & Biochemistry 67: 183-191  [pdf] Supplementary Tables   

Alster, C.J., D.P. German, Y. Lu, and S.D. Allison (2013)  Microbial enzymatic response to drought and to nitrogen addition in a southern California grassland. Soil Biology & Biochemistry 64: 68-79 [pdf] 


German, D.P.,  M.N. Weintraub, A.S. Grandy, C.L. Lauber, Z.L. Rinkes and S.D. Allison (2012)  Response to Steen and Ziergovel's comment on "Optimization of hydrolytic and oxidative enzyme methods for ecosystem studies". Soil Biology & Biochemistry 48: 198-199 [pdf]

German, D.P., K.R.B. Marcelo, M.M. Stone and S.D. Allison (2012) The Michaelis-Menten kinetics of soil extracellular enzymes in response to temperature: a cross-latitudinal study.  Global Change Biology 18: 1468-1479 [pdf]

Stone, M.M., M.S. Weiss, C.L. Goodale, M.B. Adams, I.J. Fernandez, D.P. German, and S.D. Allison (2012) Temperature sensitivity of soil enzyme kinetics under N-fertilization in two temperate forests.  Global Change Biology 18: 1173-1184 [pdf]


Lujan, N.K., D.P. German, and K.L. Winemiller (2011)  Do wood grazing fishes partition their niche? Morphological and isotopic evidence for trophic segregation in Neotropical Loricariidae. Functional Ecology 25: 1327-1338 [pdf]

German, D.P.,  M.N. Weintraub, A.S. Grandy, C.L. Lauber, Z.L. Rinkes and S.D. Allison (2011)  Optimization of hydrolytic and oxidative enzyme methods for ecosystem studies.  Soil Biology & Biochemistry 43: 1387-1397 [pdf] Please see the Corrigendum to this article, in which we correct two of the equations: equation 3 and equation 5 [pdf]  A Web of Science "highly cited paper"

German, D.P., S. Chacon and S.D. Allison (2011)  Substrate concentration and enzyme allocation can affect rates of microbial decomposition.  Ecology 92: 1471-1480 [pdf]

Day, R.D., D.P. German, J.M. Manjakasy, I. Farr, J. Hansen and I.R. Tibbetts (2011) Enzymatic digestion in stomachless fishes: how a simple gut accommodates both carnivory and herbivory. Journal of Comparative Physiology B 181: 603-613 [pdf] (New Scientist did a story on this article.  You can see it here.)

German, D.P. (2011) Digestive efficiency.  In: Encyclopedia of Fish Physiology, From Genome to Environment, Farrell A.P., J.J. Cech, J.G. Richards, and E.D. Stevens (Eds). Elsevier, San Diego, CA  (due to copyright law, I can't provide a pdf of this chapter for free on my website, but you can ask me for it!  Send me an e-mail to request a pdf)

Day, R.D., D.P. German and I.R. Tibbetts (2011) Why can't young fish eat plants? Neither digestive enzymes nor gut development preclude herbivory in the young of a stomachless marine herbivorous fish. Comparative Biochemistry and Physiology B 158: 23-29 [pdf]


German, D.P. and R.D. Miles (2010) Stable carbon and nitrogen incorporation in blood and fin tissue of the catfish Pterygoplichthys disjunctivus (Siluriformes, Loricariidae). Environmental Biology of Fishes 89: 117-133 [pdf] Supplemental Figure S1    Supplemental Figure S2

German, D.P., D.T. Neuberger, M.N. Callahan, N.R. Lizardo and D.H. Evans (2010) Feast to famine: the effects of food quality and quantity on the gut structure and function of a detritivorous catfish (Teleostei: Loricariidae). Comparative Biochemistry and Physiology A 155: 281-293 [pdf]

German, D.P., B.C. Nagle, J.M. Villeda, A.M. Ruiz, A.W. Thomson, S. Contreras-Balderas and D.H. Evans (2010)  Evolution of herbivory in a carnivorous clade of minnows (Teleostei: Cyprinidae): effects on gut size and digestive physiology.  Physiological and Biochemical Zoology 83: 1-18  [pdf]  Supplemental Table A1    Supplemental Figure A1
 the value for Campostoma anomalum Zihler's Index (ZI) in Table 3 of this paper  should be 20.76, not 2.76, as is listed.  This mistake that was missed in the proofing process.  Please make a note of this error on your copy of this article.


German, D.P. (2009) Inside the guts of wood-eating catfishes: can they digest wood?  Journal of Comparative Physiology B 179: 1011-1023 [pdf]

German, D.P. and R.A. Bittong (2009) Digestive enzyme activities and gastrointestinal fermentation in wood-eating catfishes.  Journal of Comparative Physiology B 179: 1025-1042 [pdf]

German, D.P. (2009) Do herbivorous minnows have "plug-flow reactor" guts?  Evidence from digestive enzyme activities, luminal nutrient concentrations and gastrointestinal fermentation.  Journal of Comparative Physiology B 179: 759-771 [pdf]


Gao, F., H. Yang, Q. Xu, F. Wang, G. Liu, and D.P. German (2008) Phenotypic plasticity of gut structure and function during periods of inactivity in Apostichopus japonicus (Selenka). Comparative Biochemistry and Physiology B 150: 255-262 [pdf]
German, D.P. and M.H. Horn (2006) Gut length and mass in herbivorous and carnivorous prickleback fishes (Teleostei: Stichaeidae): ontogenetic, dietary, and phylogenetic effects. Marine Biology 148: 1123-1134 [pdf] 

Horn, M.H., A. Gawlicka, D.P. German, E.A. Logothetis, J.W. Cavanagh and K.S. Boyle (2006) Structure and function of the stomachless digestive system in three related species of New World silverside fishes (Atherinopsidae) representing herbivory, omnivory, and carnivory. Marine Biology 149: 1237-1245 [pdf]

Pryor, G.S., D.P. German, and K.A. Bjorndal (2006) Gastrointestinal fermentation in greater sirens (Siren lacertina).  Journal of Herpetology 40: 112-117 [pdf]


German, D.P., M.H. Horn and A. Gawlicka (2004) Digestive enzyme activities in herbivorous and carnivorous prickleback fishes (Teleostei: Stichaeidae): ontogenetic, dietary, and phylogenetic effects. Physiological and Biochemical Zoology 77(5): 789-804 [pdf]

Sturz, A., D.P. German and D. Putnam (1998). Salton Sea Geothermal Area Mud Pots: 1991-1998. In: Geology and Geothermal Resources of the Imperial and Mexicali Valleys, L. Lindsey and W. Hample (eds). San Diego Association of Geologists publication 98-1, Pg. 109-128.